Method for the impregnation of logs



Sept. 29, 1942. K. WOLMAN' 2,297,273

METHOD. FOR THE IMPREGNATION 0F LOGS I Filed July 25, 1938 I i I lnPenlor:

Patented Sept. 29, 1942 UNITED STATES PATENT orncs 2,297,213 rm'rnon roa m marzom'rron or LOGS Karl Woiman, Berlin-Grunewald, Germany;

vested in the Alien Property Custodian Application July 25, 1938, Serial No. 221,265

In Germany August 9, 1937 2 Claims. (Cl. 117-117) It is known to impregnate logs by the sap displacement process. This is eflected by providing for example at the butt end of the log a pressure chamber into which the impregnating substance is forced by the application of pressure. From this chamber the impregnating substance passes into the sap conducting passages of the wood and displaces'the sap which passes out at the top end. It is, however, known'that this method is open to the objection that the impregnating takes a long time, on the average ten days but often much longer. Furthermore the concentration of the impregnating liquor decreases very quick- 1y on its travel through the interior of the log, so that a uniform impregnation at the butt and top ends is practically impossible to attain. These objections can be overcome by the method hereinafter described.

To effect a uniform impregnation of the particularly jeopardized butt end and the equally I the sap towards the middle where it passes out.

The method can also be carried out by acoelerating the out-flow of the sap in the middle by surrounding the exposed ring by a suction chamber, from which the sap is sucked off. 'Itis also possible, to apply'pressure selectively at the butt end or at the top end of the log while the sap is being sucked oil at the middle and no pressure is applied at the end oppodte that at which reversed. inthfltthe pressure isapplied. The method can also be impregnating substance is introduced at the middie of the log by the application of pressure and displaces the sap in two opposite directions, that is towards the butt-and top ends of the log where it flows out. Another modification of this pro-' cedure is, to suck of! selectively at the one or other end of the log the impregnating substance introduced underpressure at the. middle.

An apparatus for carrying out the invention is illustrated by way of example in the only flgure of the accompanying drawing, in which:

I designates a log, 2 a chamber at the top end, 3

. a chamber at the butt end and 4 a chamber surrounding the exposed ring, 5, 6, 'I being connections.

If pressure is applied at 2 and 3 without any suction in the middle, the chamber 4 is superfluous and can be omitted.

The method oil'ers the following advantages:

- (l) The impregnating period is considerably shortened, v

(2) The points most jeopardized are impregnated equally eifectively and l (3) The speed'of impregnation can be regu- 1 lated within wide limits. 2 Furthermore the practical advantage is attained that the exposure of the ring in the middle of the log requires very little work and time.

I claim:

- l. A method for the impregnation of. logs of any length according to the sap displacement process, consisting in disbarking the log in the middle of its length and incising the disbarked portion to a depth only suilicient to remove the entire cambium and thereby produce an. ex-

posed ring and introducing impregnating liquor at the bu'ttand top ends of the log and at the same time withdrawing the sap at the exposed ring. 1 a

2. A method as specified in claim 1, consisting '40 in forcing the impregnating liquor into one end of the log under pressure.

' WOLMAN. 

